50
The Tektronix Type 50 is a vertical plug-in for 560-series scopes. It was introduced in 1961. It is an AC amplifier with a frequency response of 15Hz to 200kHz. It provides a fixed 1mV/div sensitivity. The only control is vertical position. When paired with a Type 51 sweep, the Type 50 is useful for measurements in the audio frequency range.
Manual needed.